Question

What experiment did J. J. Thomson do?

Answer 1

In Thomson's first experiment, he discovered that cathode rays and the charge they deposited were intrinsically linked together. In the second experiment, he discovered that the charge in the cathode rays was negative. He deduced that the cathode rays were made up of negatively-charged particles.

Answer 2

$\bold{\underline{\underline{J \ J \ Thomson \ Experiment :}}}$

• The history the discovery of the smaller particles inside an atom. J J Thomson and others conducted some experiments using discharge tube apparatus.

• A discharge tube is a glass tube about 15 cm long and 3 cm diameter connected to a vacuum pump. Metal electrodes are fixed to the ends of the glass tube.

• J J Thomson created a very low pressure inside a discharge tube and applied High Voltage.
• He observed a greenish glow near the anode of the glass tube the rays which are emitted from the cathode towards the anode and caused the greenish glow. The streams of rays emitted from the cathode are called cathode rays (If you connect the plate of the discharge tube to a positive source then that plate is called anode)

• J J Thomson placed a light paddle Wheel in the path of the cathode rays, The paddle wheel started to rotate, He concluded that cathode rays are the streams of particles.

• J J Thomson applied electric field parallel to the path of the rays, The cathode rays deflected towards the anode. He concluded that cathode rays are negatively charged.

• Though J J Thomson conducted the above experiment with different gases the same results were obtained. He named this particles as electrons and stated that these electrons are negatively charged particles and the electron is lighter than hydrogen atom.